1. Technical Field
The present invention relates to an absorbent article such as a sanitary napkin. The article comprises an elongate absorbent core delimited by an upper surface and a lower surface, a pair of opposed longitudinal edge portions terminating in longitudinal edges, and a pair of opposed transverse edges. The core has a first end portion, a second end portion and a central portion located between the end portions. A liquid permeable topsheet extends over the upper surface, and a liquid barrier backsheet covers the lower surface of the absorbent core. Barrier strips are provided, each strip covering a respective longitudinal edge portion and forming a liquid-retaining pocket along each longitudinal edge portion. A pair of longitudinal elastic members is arranged along the barrier strips that are placed along each longitudinal edge portion of the absorbent core in at least the central portion of the absorbent core.
2. Discussion of Related Art
A common problem associated with an absorbent article such as a diaper or an incontinence pad, which is intended to absorb body fluid, is that fluid leaks out past the side edges of the article. Such leakage is particularly common when gushes of urine are delivered in a short time period and with a high fluid pressure. During urination, the absorbent core cannot instantly absorb all the fluid, which leads to an excessive amount of fluid that flows over the surface of the absorbent article towards the edges not only in the central portion. To help prevent side leakage, it is customary to arrange different types of leakage barriers along the side edges of the article. For example, diapers and incontinence pads are often provided with elastic members which, while the article is being used, are tightened around the user""s body and hold the side edges of the article in sealing contact against the body. Elastic members can also be used to form raised edge barriers. It is also possible to create raised barriers in other ways, for example by providing ridges or the like, which prevent liquid from flowing freely over the side edges of the article.
However, it has been found that despite all the efforts, which have hitherto been made to avoid leakage at the side edges, the problem still remains, especially in certain applications. This problem is, for instance, troublesome for bedridden individuals since the risk of leakage increases considerably when the user is lying in a side position. Body fluid which is excreted in this position runs out and gathers, by the effect of gravity, at the longitudinal side edge of the article, where the available absorption material quickly becomes oversaturated with liquid. The remaining liquid that is not absorbed can run freely along the side edge. The risk is of course great that this liquid will be forced out over the side edge of the article and escape if the user moves in such a way that a gap is formed between the article and the user""s body.
Conventional hygienic absorbent articles such as sanitary napkins, incontinence pads and the like are provided with an absorbent core which, in theory, is capable of absorbing all the fluid normally discharged by the wearer over an intended exposure time of the article. However, leakage can arise if the absorbent article is not maintained in proper relation with the wearer. One attempt to overcome this problem is to provide a sanitary napkin with so called wings. However, winged sanitary napkins also suffer from certain drawbacks. For example, if a particularly heavy discharge occurs, fluid may spread over the topsheet of the napkin and escape over the wings to thereby stain adjacent clothing. In addition, many wearers regard winged sanitary napkins as being too indiscreet.
Due to their relative narrowness, when sanitary napkins do leak this generally occurs at the side edges. Many attempts have been made to overcome the problem of edge leakage, for example by using strips of resilient material in at least the central portion of the absorbent article which increases the shape stability of the article in the strike zone, i.e. that region of the absorbent article which is first contacted by discharged bodily fluid. In this manner, the risk of bunching of the absorbent article is significantly reduced. In addition, the resilient strips press the longitudinal edges of the absorbent article towards the wearer, thereby causing the article to more readily mould to the body of the wearer. Since the strips need not extend along the entire length of the article, the article may be worn discretely. Advantageously, the remote ends of the strips may serve to impart a bowl-shape to the article to further conform the article to the shape of the wearer.
However, standing gathers is a collective name for these different types of elasticated leakage barriers along the side edges of the article, and they suffer from certain drawbacks. For example, if the standing gathers are subject to an excessive amount of external pressure due to, for example, tight trousers, a soft mattress, when the user is in a vertical position or sitting on a bicycle saddle, the standing gathers will be compressed and thereby somewhat closed, whereby the fluid is prohibited from flowing into the pockets formed by the standing gathers.
While absorbent articles having elasticated side barriers may exhibit improved side edge leakage protection when compared to an absorbent article without elasticated side barriers, a need still exists for an absorbent article which further reduces the risk of side edge leakage while still being sufficiently discrete to satisfy the majority of wearers. It is therefore an object of the present invention to provide an absorbent article that meets these requirements.
The present invention relates to an absorbent article such as a sanitary napkin. The article comprises an elongate absorbent core delimited by an upper surface and a lower surface, a pair of opposed longitudinal edge portions terminating in longitudinal edges, and a pair of opposed transverse edges. The core has a first end portion, a second end portion and a central portion located between the end portions. A liquid permeable topsheet extends over the upper surface, and a liquid barrier backsheet covers the lower surface of the absorbent core. Barrier strips are provided, each strip covering a respective longitudinal edge portion and forming a liquid-retaining pocket along each longitudinal edge portion. A pair of longitudinal elastic members is arranged along the barrier strips that are placed along each longitudinal edge portion of the absorbent core in at least the central portion of the absorbent core.
The above-stated objects are achieved in accordance with the present invention, by the absorbent article being characterised in that the elastic members include spacing means arranged at a distance from each other along the length of the elastic members. The spacing means creates fluid conducting channels that allows fluid to pass under the barrier strips into the pockets, even if the barrier strips are pressed against the top sheet due to an external force, e.g. if the user is sitting or wears tight trousers.
The elastic members may be in different shapes according to different embodiments of the invention. For instance, the elastic members may be in the shape of a string of beads, or in the shape of a string of short cylinders, or in the shape of a string of long cylinders, or there may be a distance material in the form of long cylinders placed within the barrier strips, in a direction from the center of the sanitary napkin to the longitudinal sides of the sanitary napkin.
The elastic members not only serve as means for creating channels, but may also bend the sanitary napkin into a cup-shape preferably at least partially coinciding with the wetting area.
Preferred embodiments will become evident by the subsequent dependent claims.